So I finaly picked up PTW this last Friday night and checked it out over the weekend. I played both single player and internet games.
OK, the single player changes are great:
I loved the (E)xplore option for early warrior exploration. I just crank out two or three warriors and turn them loose to map the world for me. Every once in a while I will steer one around a bit to check out specifics, but mostly I just let em run.
The new civ types are fun, and even though I have only used the Celts so far, im looking forward to trying out the rest.
The changes to the display are nice, I thought the new resource pics are good.
The A/I is smarter now! I like it!

I don't care what the devs say, the A/I is playing a better game now on Monarch than it did before. I actually lost a game the other night.
The new hot key heads up display for units is very nice.
OK, Now on to MP: (sigh)
MP sucks! I played an internet game with a friend on Sunday. We are both on cable modem, and we both use the same provider. We had green pings.
The game will lock up for extended periods of lag with no indication that it plans on comming back. If you hit commands while it is locked, they will sometimes stack and go off all at once when the game comes back.
Battles suck. The lag is bad, and if you get in a battle with someone most times it is tough just getting past the lag to get your commands in to your units before the game clock winds down. Now I love the game clock, but when the lag keeps you from even seeing what's happening, and when the screen jumps you from unit to unit before the unit you just attacked with has finished attacking, it's easy to screw up commands and get whacked by the lag gods with your turn ending while your still trying to get your units to even move, let alone attack what you are after.
When the turn starts, all the enemy units move at once. It is difficult to see what is going on. It is easy to miss units moving into your area. This would not be so bad, except that the game clock is going, and if you have to look over your entire map every turn to make sure someone is not sneeking up on you, your game clock will wind down while your looking around and not give you time to move your units too. The main problem seems to be that everything happens at once at the start of your turn, unlike the single player version where you can see the animations of the enemy units moving into your area as they happen. The MP version needs to animate each enemy unit just like the single player version, then start your game clock after they have all finished.
Random lock ups when accessing the build menu. I found that changing the build menu on a city while your turn clock is going is almost impossible. At times I would need to hit commands 5 or 6 times before they would take effect, and at times they would all go off at once and do the wrong thing.
I guess what it comes down to is that the single player version is great, but the MP version needs lots of help.